Formic acid dehydrogenation (FAD) offers an ideal route for hydrogen production, where searching for efficient and selective catalysts is imperative. However, the current state-of-the-art Pd-based metallic catalysts severely suffer from low catalytic efficiency and self-poisoning, owning to the FA dehydration side reaction. In this work, we design PANI-Pd/ C composite catalysts via interfacial microenvironment regulation technique. The as-prepared 0.01-PANI-Pd/C catalyst exhibits high turnover frequency (TOF, 5654 h(-1)) and excellent resistance to CO poisoning. The merit of polyaniline can be ascribed to: a) con- struction of abundant Pd-PdO interfaces; b) capturing H+ and accelerating the formation of the reactive species. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.